In healthy young adults: A. Ingestion of a high fat diet for 96 hours will decrease 24-h Growth Hormone (GH) release and the GH response to acute exercise compared to a normal mixed diet. B. Ingestion of a high carbohydrate diet for 96 hours will increase 24-h GH release and the GH response to acute exercise compared to a normal mixed diet. No additional subjects are being entered in this study. All data have been collected. We have been analyzing data and waiting for assayed data to beome available. This was DIETARY and COMPUTER LAB Only.